<?php

/*
 * This file is part of the Symfony package.
 *
 * (c) Fabien Potencier <fabien@symfony.com>
 *
 * For the full copyright and license information, please view the LICENSE
 * file that was distributed with this source code.
 */

namespace Symfony\Component\Console\Input;

/**
 * Represents a command line argument.
 *
 * @author Fabien Potencier <fabien@symfony.com>
 *
 * @api
 */
class InputArgument {
	const REQUIRED = 1;
	const OPTIONAL = 2;
	const IS_ARRAY = 4;
	
	private $name;
	private $mode;
	private $default;
	private $description;
	
	/**
	 * Constructor.
	 *
	 * @param string  $name        The argument name
	 * @param integer $mode        The argument mode: self::REQUIRED or self::OPTIONAL
	 * @param string  $description A description text
	 * @param mixed   $default     The default value (for self::OPTIONAL mode only)
	 *
	 * @throws \InvalidArgumentException When argument mode is not valid
	 *
	 * @api
	 */
	public function __construct($name, $mode = null, $description = '', $default = null) {
		if( null === $mode ) {
			$mode = self::OPTIONAL;
		} else if( is_string( $mode ) || $mode > 7 ) {
			throw new \InvalidArgumentException( sprintf( 'Argument mode "%s" is not valid.', $mode ) );
		}
		
		$this->name = $name;
		$this->mode = $mode;
		$this->description = $description;
		
		$this->setDefault( $default );
	}
	
	/**
	 * Returns the argument name.
	 *
	 * @return string The argument name
	 */
	public function getName() {
		return $this->name;
	}
	
	/**
	 * Returns true if the argument is required.
	 *
	 * @return Boolean true if parameter mode is self::REQUIRED, false otherwise
	 */
	public function isRequired() {
		return self::REQUIRED === (self::REQUIRED & $this->mode);
	}
	
	/**
	 * Returns true if the argument can take multiple values.
	 *
	 * @return Boolean true if mode is self::IS_ARRAY, false otherwise
	 */
	public function isArray() {
		return self::IS_ARRAY === (self::IS_ARRAY & $this->mode);
	}
	
	/**
	 * Sets the default value.
	 *
	 * @param mixed $default The default value
	 *
	 * @throws \LogicException When incorrect default value is given
	 */
	public function setDefault($default = null) {
		if( self::REQUIRED === $this->mode && null !== $default ) {
			throw new \LogicException( 'Cannot set a default value except for Parameter::OPTIONAL mode.' );
		}
		
		if( $this->isArray() ) {
			if( null === $default ) {
				$default = array();
			} else if( !is_array( $default ) ) {
				throw new \LogicException( 'A default value for an array argument must be an array.' );
			}
		}
		
		$this->default = $default;
	}
	
	/**
	 * Returns the default value.
	 *
	 * @return mixed The default value
	 */
	public function getDefault() {
		return $this->default;
	}
	
	/**
	 * Returns the description text.
	 *
	 * @return string The description text
	 */
	public function getDescription() {
		return $this->description;
	}
}
